KR200305730Y1 - Apparatus for disposing waste water - Google Patents

Abstract

The present invention relates to a water treatment apparatus, comprising: a floating tank for treating waste water; A dissolved water input unit for forming a microbubble in the floating tank by dissolving a relatively large amount of air while maximizing the dissolution time and air pressure for dissolving air in the water and introducing the dissolved water into the floating tank; It is characterized in that it comprises a scum removal unit provided on the upper side of the floating tank to filter the waste water wastes floated to the upper side of the floating tank by the microbubble. As a result, by reducing the amount of dissolution time and pressure required for dissolving as conventionally, the efficiency of wastewater treatment in the flotation tank can be increased, and a large amount of air can be dissolved in a simple structure and method. A water treatment apparatus is provided, which makes it possible to compact the size of the treatment apparatus.

Description

Apparatus for disposing waste water

The present invention relates to a water treatment device, and more particularly, to significantly reduce the dissolution time and the pressure required for dissolution as in the prior art to increase the efficiency of wastewater treatment in the flotation tank, while maintaining a simple structure and The present invention relates to a water treatment apparatus capable of compacting a scale of a treatment apparatus by allowing a large amount of 42a of air to be dissolved in a method.

As the industry is highly developed, the seriousness of environmental pollution is increasing day by day. In particular, wastewater, factory wastewater, and livestock wastewater (hereinafter collectively referred to as "wastewater") discharged from homes, factories, or livestock houses flow into groundwater and rivers and eventually pollute the sea.

As such, if the wastewater is discharged as it is without purification, various organic matters, microorganisms, nitrogen (N), phosphorus (P), etc., cause river erosion, which causes not only the destruction of the aquatic ecosystem but also pollution of the soil. By destroying the food chain of the living environment and ecosystems, we have no choice but to threaten human right to life.

Of course, in order to reduce such damages, it is most desirable to basically reduce the discharge of wastewater, but as the industry develops, discharge of various wastewater is inevitable.

Therefore, it is necessary to develop a method capable of appropriately treating such wastewater, and in recent years, many researches and investments have been made on wastewater treatment apparatuses capable of treating wastewater in various layers. The wastewater treatment method is largely divided into physical treatment, chemical treatment or biological treatment.

In the physical treatment method, for example, fine bubbles are made to float to the upper side of the flotation tank so that the dirt in the waste water collides with the fine bubbles, which is often referred to as a pressure injury device. This pressurization apparatus is widely applied to industrial wastewater and general sewage treatment plants, and uses so-called D.A.F (Dissolved Air Flotation) system to form fine bubbles.

The application of DAF is also known as a device that directly dissolves air through a compressor, but there is a difficulty in installing a pipe that requires a long distance. Therefore, forced air is dissolved in a constant pressure vessel, The method used in the form of bubbles is widely applied.

In the state of supplying water at a certain position to a constant pressure vessel, the air is dissolved by supplying compressed air at a pressure of 4 ~ 6kgf / cm ² using a device that compresses the air, such as a compressor, to the water in the pressure vessel. Of course, the dissolved state of air depends on the nature of the water and takes a certain dissolution time to completely dissolve the air.

After discharging the air for about 30 seconds, a certain amount of air is dissolved in the water in the pressure vessel, and the pressure reducing valve is opened. After inflow, it floats to the upper side of the floating tank in the form of microbubbles.

This floating microbubble is in contact with the waste in the waste water to rise to the upper side. When the dirt rises to the upper side of the floating tank by the microbubble, the scum removing unit disposed on the upper side of the floating tank is filtered to one side.

However, in the water treatment apparatus to which the D.A.F is applied, the dissolution time for dissolving air in the water in the pressure vessel is very long, and there is a disadvantage of causing a safety problem due to high pressure in the pressure vessel when dissolved. If the dissolution time is to be shortened, the volume of the pressure vessel must be increased, but there is a limit to manufacturing the volume of the pressure vessel indefinitely.

Therefore, in the related art, it is necessary to take a certain dissolution time and install several pressure vessels for air dissolution. Therefore, the size of the treatment device is inevitably increased, and wastewater cannot be treated during the dissolution time. There is this.

Accordingly, an object of the present invention is to significantly reduce the dissolution time and pressure required for dissolution as in the prior art, thereby increasing the efficiency of wastewater treatment in the flotation tank, while providing a large amount of air with a simple structure and method. It is possible to provide a water treatment apparatus that can be made compact so that the size of the treatment apparatus can be made compact.

1 is a schematic view of a water treatment apparatus according to an embodiment of the present invention,

2 is an enlarged view of the dissolved water input region;

3A and 3B are front and rear views of the backflow preventing plate of the dissolved water input unit, respectively,

3c is an enlarged view of the bubble generating member;

4A and 4B show an embodiment of a pressure vessel, respectively;

5A and 5B show an embodiment of the inclined head region, respectively;

6A and 6B illustrate an embodiment of a scum removing unit, respectively;

7 is a schematic view of a water treatment device according to another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: floating tank 12a, 12b: first and second intermediate partition wall

40: wastewater supply unit 50: dissolved water input unit

51: inclined head portion 56: backflow prevention plate

57: front panel 58: rear panel

60: scum removal unit 62: chain

63: dirt removal bar 64: rotating pin

65: anti-rotation jaw 66: pressure vessel

70: bubble generator

The object is, according to the present invention, a flotation tank for treating waste water; A dissolved water input unit for forming a microbubble in the floating tank by dissolving a relatively large amount of air while maximizing the dissolution time and air pressure for dissolving air in the water and introducing the dissolved water into the floating tank; It is achieved by a water treatment apparatus provided in the upper portion of the floating tank and comprises a scum removal unit for filtering the waste water of the waste water floated to the upper side of the floating tank by the microbubble.

Here, the dissolved water inlet is connected to a treatment water movement line, one end of which is provided at one side of the flotation tank and moves the treated water filtered by the scum removal unit, and the other end is disposed in the flotation tank to circulate water. Wow; A bubble generator disposed on a line of the circulation passage for dissolving air in the treated water; A pressure vessel provided on a circulation passage between the bubble generator and the floating tank; An air supply unit provided outside the line of the circulation passage to supply air to the bubble generator; And a pump for pumping a portion of the treated water in the treated water moving line to the bubble generating device on a circulation passage between the bubble generating device and the treated water moving line.

The bubble generating apparatus includes: a main body tube formed on a line of the circulation passage and having a diameter larger than that of the circulation passage and formed of a plurality of tubes separated and coupled to each other along a water traveling direction; A plurality of through holes, one end of which is detachably coupled to the supply pipe of the air supply unit, the other end of which is closed and disposed at the rear of the main body pipe, and formed on a side wall to generate bubbles, and at least one of which is in close contact with each of the through holes. It includes a bubble generating member having an airtight member.

The main tube is separated into a first tube, a second tube and a third tube along the water running direction, and the first to third tubes are formed with a flange portion to which the coupling member is coupled, and the second tube and the third tube. A gasket and a backflow preventing plate are provided between the flange portions of the three pipes.

The non-return plate includes a front plate made of stainless steel and a back plate made of plastic material with respect to the moving direction of water, and a plurality of relatively fine holes are formed in a central area of the front plate, and the front plate has the front plate. A pair of half moon openings are formed in the horizontal direction outer side of the hole formed in the board.

It further comprises a micro-bubble floating portion provided in the floating tank to float the micro-bubbles to the upper side of the floating tank.

The microbubble floating portion is an inclined head portion disposed on one side wall of the flotation tank and formed with a plurality of microbubble discharge holes formed on an inclined surface so as to shoot microbubbles mixed with waste water in an inclined direction, and the microbubble discharge hole has a high The smaller the size is from the side toward the lower side.

The scum removing unit includes a drive motor, a pair of gears spaced apart from each other and rotated by the drive motor; A chain for interconnecting the pair of gears; One side free end is rotatably coupled to the chain in one direction so as to face the flotation tank, while moving along the chain to filter the dirt floated to the upper side of the flotation vessel by a microbubble to the waste treatment unit disposed on one side of the flotation vessel The interior includes a plurality of decontamination bars.

Hereinafter, with reference to the accompanying drawings will be described in detail for each embodiment of the present invention, and the same reference numerals for the same configuration of the description of each embodiment.

In the water treatment apparatus according to the embodiment of the present invention, as shown in FIG. 1, the floating tank 10 for treating wastewater and the dissolved dissolved water into the floating tank 10 are introduced into the floating tank 10. Dissolved water input unit 50 for forming micro bubbles within the) and scum removal unit for filtering waste water that is provided on the floating tank 10 to the upper side of the floating tank 10 by the micro bubbles. (60).

In the floating tank 10, the lower end thereof is spaced upwardly from the bottom of the floating tank 10, and the second intermediate partition 12b disposed to correspond to the first intermediate partition 12a and the first intermediate partition 12a. ) Is provided. The treated water treated in the floating tank 10 is moved through the right treatment water movement line 30 of the floating tank 10 in the drawing through these first and second intermediate partitions 12a and 12b.

One side of the floatation tank 10 is provided with a waste treatment unit 20 containing dirt filtered by the scum removal unit 60, which will be described later, and the other side of the floatation tank 10 moves the treated water to move the treated water to another place. Line 30 is provided. The treatment water movement line 30 is provided with a valve 30a for supplying water in the treatment water movement line 30 to another place. Typically, the treated water is supplied to another place through the treated water moving line 30, but in the present invention, a portion of the treated water is recycled to the dissolved water input unit 50 through a predetermined branch valve 30b.

One side of the floating tank 10 is provided with a waste water flow passage 42 for introducing industrial wastewater and general sewage into the floating tank 10. And, one side in the floating tank 10 is provided with a bubble floating portion for floating the fine bubbles to the upper side of the floating tank 10, when dissolved water flows into the floating tank (10).

Dissolved water input portion 50, one end is provided on one side of the floating tank 10 is connected to the treated water transfer line 30 for moving the treated water filtered by the scum removal unit 60 and the other end is a wastewater flow path A circulation passage 52 connected to 42 to circulate the treated water, a bubble generator 70 disposed on a line of the circulation passage 52 to dissolve air in the treated water, and a bubble generator 70; And the pressure vessel 66 provided on the circulation passage 52 between the wastewater passage 42 and the outside of the line of the circulation passage 52 to supply air to the bubble generating member 72 of the bubble generator 70. A part of the treated water in the treated water moving line 30 is disposed on the circulation passage 52 between the air supply unit (not shown) to supply and the bubble generating device 70 and the treated water moving line 30. A pump 77 pumping to 70).

As shown in FIG. 2, the bubble generator 70 is disposed on a line of the circulation passage 52 and has a diameter larger than that of the circulation passage 52 and supplies high pressure compressed air from an air supply to one side. Main body tubes 71a to 71c and bubble generation members 72 provided in the main body tubes 71a to 71c.

The main tubes 71a to 71c are separated into a first tube 71a, a second tube 71b, and a third tube 71c along the advancing direction of water, and are coupled to each other. To this end, flange portions 73 are formed in the first to third pipes 71a to 71c, respectively, and these flange portions 73 are coupled by the coupling member 74.

Also in the second pipe 71b and the third pipe 71c, a flange portion 73 which can be engaged by the coupling member 74 is also formed, and between the flange portions 73 along the traveling direction of the water gasket ( 75) and a non-return plate 56 is provided. Although not shown, a gasket is advantageously provided between these flange portions 73.

As shown in FIGS. 2A and 2B, the non-return plate 56 includes a front plate 57 made of stainless steel and a back plate 58 made of plastic. A plurality of relatively fine holes 57a are formed in the central region of the front plate 57, and a pair of half moon openings 58a are formed outside the holes 57a formed in the front plate 57 in the rear plate 58. Is formed, a plurality of through-holes (58b) for the passage of the coupling member 74 on the outside of the front plate 57 and the back plate 58 is formed.

Thus, when a fine bubble is generated by the bubble generating member 72 to be described later, first exits through the hole 57a formed in the central region of the front plate 57 along the water traveling direction. However, the bubble escaped through the hole 57a of the front plate 57 hits the central region of the rear plate 58 and is split in detail, and then discharged through the half moon opening 58a formed at one side thereof. . Therefore, the non-return plate 56 serves to prevent the microbubbles from flowing backward and to form a smaller bubble.

As shown in FIG. 3C, the bubble generating member 72 disposed in the second pipe 71b is detachably coupled to the supply pipe 59a of the air supply part by opening one end 72a of the air tube (normal thread type). The other end 72b is closed and is arrange | positioned at the rear end of the 2nd pipe 71b. At this time, if the bubble generating member 72 is to be replaced, the other end 72b of the bubble generating member 72 is replaced with a separate tool while the second pipe 71b and the third pipe 71c are separated. Just do it.

A plurality of through holes 72a are formed on the sidewall of the bubble generating member 72 for generating micro bubbles, and each of the through holes 72a is tightly surrounded by a hermetic member 76 by a band 76a. have. The airtight member 76 is arrange | positioned in multiple numbers along the longitudinal direction of the bubble generating member 72, and the number can be suitably employ | adopted according to the generation degree of foam.

Accordingly, when air is forced into one side of the bubble generating member 72 through the supply pipe 59a of the air supply unit while water continues to flow into the main body tubes 71a to 71c, the other side of the bubble generating member 72 In a closed relationship, the air emerges in the form of bubbles through a narrow space between the airtight member 76 and the bubble generating member 72 through each through hole 72a of the bubble generating member 72 (see FIG. 3C). Arrow) and dissolved in water flowing into the main body tubes 71a to 71c. Therefore, the dissolution time is significantly reduced as compared with the conventional. Dissolved water in which air is dissolved is circulated through the pressure vessel 66 along the circulation passage 52 to be introduced into the flotation tank 10.

As such, the fine bubbles are generated by the bubble generating member 72 and the dissolved water flowing along the circulation passage 52 reaches the pressure vessel 66 in a state where the bubbles are broken again through the backflow prevention plate 56. .

At this time, the bubbles dissolved in the water reaching the pressure vessel 66 should temporarily stay in a relatively stable state in the pressure vessel 66, as shown in Figure 4a, the inlet end of the pressure vessel 66 ( In the adjacent region of 66a), it is preferable that a guide guide 66c is provided to guide the movement of water so that the water in which the bubbles are dissolved does not slump and descends gradually along the inner wall surface of the pressure vessel 66.

Water introduced into the inlet end 66a by the guide guide 66c gradually flows down the inner wall surface of the pressure vessel 66 while being guided to both sides by the guide guide 66c, and then the outlet end 66b. Can be supplied into the flotation tank 10 through.

As shown in FIG. 5A, the bubble floating portion is disposed on one side wall in the floating tank 10 and a plurality of fine bubble discharge holes 51c on the inclined surface 51b so as to shoot the microbubbles mixed with the waste water in an inclined direction. ) Is formed by the inclined head portion 51a. At this time, the distance in which the fine bubbles rise can be adjusted according to the angle of the inclined surface 51b, the discharge hole 51c is formed smaller in size from the higher side to the lower side.

This is because the microbubble disposed on the higher slope takes less time to rise to the surface and the microbubble disposed on the lower gradient takes much time to rise to the surface, and the size of the discharge hole 51c is different. It is given.

Thus, the dissolved water introduced into the end of the circulation passage 52 is sequentially filled from the bottom of the inclined head portion 51a through the downward discharge hole 52a formed at the end of the circulation passage 52, and then of different sizes. It is discharged through the discharge hole 51c. In the process of discharge, the air in the dissolved water rises in the form of fine bubbles while colliding with the waste water waste and floating upward.

As such, when the micro bubbles rise to the upper side in the flotation tank 10, the dirt in the waste water is buried in the microbubbles and floats upward. The dirt floated upward by the microbubbles is transferred to the dirt treatment part 20 by the scum removal part 60.

As shown in FIG. 6A, the scum removing unit 60 is a pair of gears 61 that are spaced apart from each other and rotated by a driving motor (not shown), and a chain 62 that interconnects the pair of gears 61. ).

While moving along the rotating chain 62, the chain 62 filters the dirt floating on the upper side of the floating tank 10 by the microbubbles to the waste disposal unit 20 disposed on one side of the floating tank 10. A plurality of dirt removal bars 63 are rotatably coupled to the chain 62 in one direction.

Conventional dirt removal bars are not shown, but their exposed ends have always been radially outward. However, in the present invention, the dirt removal bar 63 is rotatably coupled to the chain 62 while not rotating in the direction opposite to the moving direction of the chain 62.

To this end, the dirt removal bar 63 is rotatably coupled to the chain 62 by a pivot pin 64, and rotation of the chain 62 between the side of the dirt removal bar 63 and the chain 62. The reverse rotation prevention jaw 65 which prevents the dirt removal bar 63 from rotating in the opposite direction is provided.

Due to the pivot pin 64 and the reverse rotation prevention jaw 65, the plurality of dirt removal bars 63 may have their exposed ends always facing the float 10. Therefore, unnecessary power loss can be reduced, and the scale of the water treatment device can be made compact.

As shown in Figure 6a, the dirt removal bar 63 is disposed in the lower portion of the belt 62 to remove the dirt, and then moved along the belt 62 and moved to the upper portion of the belt 62, the dirt removal bar ( If the surface tension of the water buried on the surface of 63) is lower than the gravity, it falls back to the floatation tank 10. In the conventional water treatment apparatus, the water drop is relatively large so that the water in the flotation vessel 10 falls. Inevitably cause a lot of shaking.

However, since the dirt removal bar 63 employed in the water treatment apparatus of the present invention always faces downward of resin, even if water adhered to the dirt removal bar 63 falls, the drop distance is short, so that the water fall within the flotation tank 10 may be reduced. Fluctuations in the water does not occur badly, there is an effect that the efficiency of filtering the dirt by the dirt removal bar (63) does not decrease.

In addition, when the conventional waste removal bar is obtained with water in the floatation tank 10, its area of inflow becomes wider, and it causes severe fluctuations in the water in the floatation vessel 10, but it is employed in the water treatment apparatus of the present invention. The dirt removal bar 63 has a form in which only its end is obtained, so that the area of acquisition is significantly smaller than in the prior art. Therefore, it is possible to improve the efficiency of filtering the dirt by preventing the water in the floating tank 10 to swing to the maximum.

Although not shown in order to allow the waste filtered by the scum removal unit 60 to be easily introduced into the waste disposal unit 20, the area connecting the floating tank 10 and the waste disposal unit 20 may be inclined at a constant angle. It would be more advantageous to form.

By such a configuration, if air is forced into one side of the bubble generating member 72 through the supply pipe 59a of the air supply unit while water continues to flow into the main body tubes 71a to 71c, the bubble generating member 72 is formed. Since the other side of the air is closed, the air comes out in the form of bubbles through a narrow space between the airtight member 76 and the bubble generating member 72 through each through hole 72a of the bubble generating member 72 ( 3c), dissolved in water flowing into the body pipes 71a to 71c, and circulated through the pressure vessel 66 along the circulation flow path 52 to be introduced into the floating tank 10. As shown in FIG.

Dissolved water reaching the pressure vessel 66 should be temporarily maintained in a relatively stable state in the pressure vessel 66. In the pressure vessel 66, a guide guide 66c is provided, so that the pressure vessel 66 is not swung. It is gradually lowered along the inner wall of the back and is supplied to the flotation tank 10 through the circulation passage (52).

Dissolved water introduced into the end of the circulation passage 52 is sequentially filled from the bottom of the inclined head portion 51a through a downward discharge hole 52a formed at the end of the circulation passage 52, and then discharge holes having different sizes. It is discharged through 51c.

In the discharge process, air in the dissolved water collides with the waste water in the form of microbubbles and floats upward. After the injury, the air in the dissolved water is lifted by one of the scum removing bars 63 of the scum removing unit 60. Is transferred to the waste treatment unit 20.

As described above, according to the present invention, a relatively large amount of dissolution time and pressure required for dissolution are significantly reduced as in the prior art, while the efficiency of wastewater treatment in the flotation tank 10 is increased, while a large amount is available in a simple structure and method. By allowing air to be dissolved, the size of the processing apparatus can be made compact.

In addition, since the exposed end of the dirt removal bar 63 always faces the flotation tank, unnecessary power loss can be reduced, and the size of the water treatment apparatus can be made compact. And, even if the water on the dirt removal bar 63 falls into the flotation tank, the fall distance is reduced, so that not only the shaking in the water in the flotation tank 10 can be prevented from occurring severely, but also into the flotation tank 10. By reducing the acquisition area of the dirt removal bar 63 to be obtained, it is possible to prevent the fluctuation of the water in the floating tank 10 to occur badly and to increase the dirt removal efficiency.

Although one embodiment of the present invention has been described in detail above, the spirit of the present invention is not limited thereto.

In the above-described embodiment, the floating tank 10 has a rectangular cylinder shape in which the upper side is opened. However, this is only one embodiment, the shape of the floating tank 10 may be made of other shapes.

In addition to the pressure vessel 66 shown in Figure 4a of the above-described embodiment, as shown in Figure 4b, inlet in the state provided with a water reservoir 67 formed with a water discharge hole 67 'in the pressure vessel 66' The stage 66a 'is connected to the water reservoir 67, and the outlet 66b' is disposed in the space between the pressure vessel 66 'and the water reservoir 67 so that the water in which the microbubbles are dissolved is once water. It may be introduced into the reservoir 67 and slowly filled up, and then discharged into the pressure vessel 66 'through the water discharge hole 67', and then directed to the flotation tank 10 through the outlet end 66b '. . This is illustrated by the arrow.

In addition to FIG. 5A of the above-described embodiment, as shown in FIG. 5B, a horizontal partition plate 51d having a separate water passage hole 51e is further formed in the inclined head portion 51a to form water in the circulation flow path 52. It may be to be discharged to the discharge hole (51c) through the water through hole (51e) of the horizontal plate (51d). At this time, an upper portion of the horizontal plate 51d is provided with a pipe 53 through which wastewater flows.

In FIG. 1 of the above-mentioned embodiment, the bubble floating part is made into the inclined head part 51a. However, the bubble floating portion may be a rod-shaped floating bar disposed long at the bottom in the floating tank 10.

6A of the above-described embodiment, it can be seen that the dirt removal bar 63 has a straight rod shape. However, in order to increase the efficiency of dirt removal, as shown in FIG. 6B, the dirt removal bar 63 ′ is advantageously disposed at an angle to the chain 62 so that the end 63 a ′ is vertical. . In addition, the technique of always facing the end (63a ', also referred to as a free end) of the dirt removal bar 63 will be able to employ a variety of methods in addition to the above-described method.

In the above-described embodiment, the dissolved water is introduced into the flotation tank 10 in a state in which the dissolved water is combined, but as shown in FIG. 7, the wastewater flows into the flotation tank 10 through the wastewater flow passage 42 and is dissolved. The water may be introduced into the flotation tank 10 through a separate line 42a from the wastewater channel 42.

Although not shown and described in the above-described embodiment, when the weight of the waste in the waste water is large, it may not rise upward due to the microbubbles. Such dirt is sinked to the lower part in the floating tank 10, by providing a screw member on the lower part in the floating tank 10, the lower part of the floating tank 10 by providing a separate filter bin, You might be able to filter it out with a screw.

In addition, if a separate filter and filter net is further provided on the second intermediate partition 12b of the floating tank 10, the scum removing unit 60 may provide the effect of filtering out the secondary soil.

As described above, according to the present invention, it is possible to significantly reduce the dissolution time and the pressure required for the dissolution as in the prior art, thereby increasing the efficiency of wastewater treatment in the flotation tank, and by using a simple structure and method. A water treatment apparatus is provided that enables the air to be dissolved so that the size of the treatment apparatus can be made compact.

In addition, even if water adhered to the decontamination bar falls into the flotation tank, the falling distance is reduced, which prevents severe fluctuations in the water in the flotation tank. Reducing it can prevent excessive fluctuations in the water in the flotation tank, thereby improving the efficiency of the removal of dirt.

Claims (8)

A flotation tank for treating waste water; A dissolved water input unit for forming a microbubble in the floating tank by dissolving a relatively large amount of air while maximizing the dissolution time and air pressure for dissolving air in the water and introducing the dissolved water into the floating tank; And a scum removal unit provided at an upper portion of the floating tank to filter out wastewater from the waste water floating above the floating tank by the microbubbles. The method of claim 1, The dissolved water injection portion, A circulation passage having one end connected to a treatment water moving line provided at one side of the floating tank and moving the treated water filtered by the scum removing unit, and the other end disposed at the floating tank to circulate water; A bubble generator disposed on a line of the circulation passage for dissolving air in the treated water; A pressure vessel provided on a circulation passage between the bubble generator and the floating tank; An air supply unit provided outside the line of the circulation passage to supply air to the bubble generator; And a pump for pumping a part of the treated water in the treated water moving line to the bubble generating device on a circulation passage between the bubble generating device and the treated water moving line. The method of claim 2, The bubble generator, A main body tube disposed on a line of the circulation passage and having a larger diameter than the circulation passage and formed of a plurality of tubes separated and coupled to each other along a traveling direction of the water; A plurality of through holes, one end of which is detachably coupled to the supply pipe of the air supply unit and the other end of which is closed and disposed at the rear of the main body pipe, formed on the side wall to generate micro-bubbles, and at least tightly coupled to the respective through holes A water treatment apparatus comprising a bubble generating member having one hermetic member. The method of claim 3, The main body pipe is separated into a first pipe, a second pipe and a third pipe along the water traveling direction, the first to third pipes are formed with a flange portion to which the coupling member is fastened, Gasket and backflow prevention plate is provided between the flange portion of the second pipe and the third pipe. The method of claim 4, wherein The non-return plate includes a front plate made of stainless steel and a back plate made of plastic material with respect to the moving direction of water, and a plurality of relatively fine holes are formed in a central area of the front plate, and the front plate has the front plate. A water treatment device, characterized in that a pair of half moon openings are formed in the horizontal direction outside of the hole formed in the plate. The method of claim 2, And a microbubble floater provided in the floatation tank to float the microbubbles above the floatation tank. The method of claim 6, The microbubble floating portion is an inclined head portion disposed on one side wall of the flotation tank and formed with a plurality of microbubble discharge holes formed on an inclined surface so as to shoot microbubbles mixed with waste water in an inclined direction, and the microbubble discharge hole has a high The water treatment apparatus, characterized in that the size is formed smaller from the side toward the lower side. The method of claim 1, The scum removing unit, Drive motor, A pair of gears spaced apart from each other and rotated by the drive motor; A chain for interconnecting the pair of gears; One side free end is rotatably coupled to the chain in one direction so as to face the flotation tank, while moving along the chain to filter the dirt floated to the upper side of the flotation vessel by a microbubble to the waste treatment unit disposed on one side of the flotation vessel The water treatment apparatus, characterized in that it comprises a plurality of dirt removal bar.